Evaporator for household refrigerators



March 54, 1940. s. F. BRlGGs 2,192,431

u EVAPORATOR FOR HOUSEHOLD REFRIGERATORS Filed Sept. 6, 1938 2 Sheets-Sheet 1 INVENTOR.

f ATroRNEYs .Mmm

March 5, 1940. s, F, BRlGGs 2,192,431

EvAPonAToR Fon HousEaoLn REFnrGERAToRs Filed sept. s, 1938 2 sheets-sheet 2 1 l ila wir fit1; 11: "i2-7- I N VENT OR. 5750/15# E @fe/665 ATTORNEYS Patented Mar. 5, 1940 UNITED STATES PATENT OFFICE EVAPORATOR FOR HOUSEHOLD REFRIG- ERATORS Application September 6, 1938, Serial No: 228,473

2 Claims.

AI'his invention .relates to improvements in evaporators for household refrigerators.

It is Ithe primary object of the invention to provide a novel and inexpensive evaporator unit constituting a freezing chamber having a preformed evaporator coil embedded in its wall surfaces. It is a further object of the invention to provide a combined freezing chamber and evaporator in which the passages constituting the evaporator coil' extend continuously within a chamber which is substantially closed against air circulationand which is provided with heat exchange surfaces on its external Walls for the refrigeration of a food compartment by heat absorption and conduction to and through the material of the chamber as distinguished from the use of an exposed evaporator coil.

It is my further purpose preferably to remove the evaporator passages largely to the interior partitions of such a freezing chamber so as to produce a sharptemperature variation between the freezing lchamber and the refrigerating compartment in which such a chamber is located, the major portion of the exposed surfaces of the refrigerating chamber being free of evaporator passages or coils whereby to minimize the formation of frost by condensation thereon.

Other objectswill appear in more detail from the following disclosure.

In the drawings:

Figure 1 is a view in perspective of a completed freezing chamber and unitarily incorporated evaporator coil embodying this invention.

Figure 2 is a view in perspective of a preformed evaporator coil unit which is embedded by molding or otherwise in the completed chamber illustrated in Figure 1.

Figure 3 is a view on an enlarged scale showing in transverse section th'e completed unit illus` trated in Figure 1.

Figure 4 is a view partially in plan and partially in horizontal section as indicated by line 4 4 of Figure 3.

Like parts are represented by the same referende characters throughout the several views. f

My 4improved evaporator and refrigerating chamber unit comprises a cell or casing 5 which is die cast, molded or cast to provide in one,

single integral unit atop. 6, a bottom 1, side walls 8 and 9 and a back I0. Externally, the top, the side walls and the bottom are encircled by closely adjacent ribs I5 which reenforce the wall structure and also provide a greatly increased heat absorption surface. Interiorly. certain of the walls, preferably the side walls 8 and 9 and the rear wall Il), are connected by partitions I6 and I1 which, together with the bottom 1, serve as supports for the usual freezing trays. Obviously, the resulting integral structure is extremely strong, even though the metal constituting its wall surfaces may be very light. At the front of the unit, the partitions or shelves I6 and I1 and the several top, bottom and side walls 6, 1, 8 and 9 terminate in a preferably planeform finished surface at I8, against which the door i9 may tightly close. Such surface may be. provided integrally with tiers to receive the door hinge pintles. Also'formed integrally with the unit I prefer to provide the supporting brackets 2I whereby the unit may be suspended for operation within the usual food compartment of the household type of refrigerator, it being intended that such food compart ment shall be refrigerated -by the absorption of heat therefrom through the flanges I5 and other exposed interior surfaces of the unit.

The interior of the one piece molded unit is provided in any desired manner with evaporator coil passages for the refrigerant. Such passages are preferably, however, limited largely to the partitions I6 and I1, the bottom wall 1 being also used if desired. By omitting coils'or passages from the side and top walls, I can tend l `to prevent the formation of frost thereon, as

the. interior of the several compartments into which the freezing chamber is subdivided by partitions I6 and l1 can be maintained very cold Without having the exterior ofthe unit fall appreciably, if at all, below the .freezing point.

For economy of manufacture, .it is preferred that these passages or coils be pre-formed of copper tubing or the like. In Figure 2, I have illustrated the pre-formed tube unit in which a single piece of tubing is bent to provide a stratum'of convolutions at 22 connected by a. vertical run 23 with a second stratum of convolutions at 24, this being in turn connected by a vertical run 25 with another stratum of convolutions at 26. The cnvolutions of Athe top and bottom strata 22 and 26 are respectively connected with the supply pipe 21 and the return pipe 28 which, in turn, lwill be connected to the usual reducing valve and the high and low pressure sides respectively of the, refrigerating system. l

The pre-formed coil, made in accordance with Figure 2 or otherwise, is inserted in a mold `or die and the material used to make the chamber 5 is molded vor cast about it. Metal such as the aluminum alloys used for die casting is preferred but plastic and other material, even including high temperature differentiation maintained between the'interior of the chamber and the exterior food compartment in which the chamber is disposed in the refrigerator. Ice can be frozen speedily without unduly chilling the food in the refrigerator cabinet and the device will function vover long periods without requiring defrosting.

I claim:

1. The combinationwith a pipe pre-formed to provide a plurality of. series of convolutions disposed horizontally at different levels and'provided with communicating sections extending between said levels at the ends of saidv series andv serving to connect the several convolutions in sequence, of a chamber constituting material cast -to provide integrally connected top, side, bottomA and end walls'andv at least one horizontal partltion, the convolutions of said pipe atv one of saidA levels being embedded in said partition and said communicating sections being embedded in said end'wall respectively, the top, side and bottom walls of said chamber being provided integrally with external flanges and the side and top walls being substantially free of said pipe, whereby the interior of said chamber lis primarily refrigerated,

and air circulated by gravity over said chamber, and encountering flanges ofthe top and -side walls of said chamber is refrigerated secondarily by conduction through the material of said walls.

2. 'I'he combination with a pipe preformed to lprovide a plurality of-series of convolutions disposed horizontally at differing levels and providedwith communicating sections extending between said levels and serving to connect the several convolutions in series, of a chamber constituting material cast to provide integrally connected top, side, bottom and end walls and at least one' horizontal partition, diifering convolutions of said.

pipe being embedded in a partition and bottom wall, respectively, thetop, side and'end walls' of said chamber being substantially free of said pipe other ,than said communicatingl sections, whereby the interior of said chamber is'primarily y chilled, the air circulated by gravity and encountering the top and side walls of said chamber being chilled by conduction through the walls thereof.

' STEPHEN F. BRIGGS. 

